The healthiness of a kidney transplant is conventionally assessed by measuring creatinine levels in the blood. An increase in creatinine is called allograft dysfunction. Two types of acute rejection are the more common cause of allograft dysfunction: acute cellular and acute antibody mediated. Accurate diagnosis is important for providing that will provide treatment that is optimally therapeutic.
When the creatinine levels increase, patients typically undergo an invasive needle biopsy of the transplanted kidney to confirm acute rejection. However an increase in creatinine is not a specific test for acute rejection and a sizable proportion of patients with allograft dysfunction do not have acute rejection on biopsy. Moreover, invasive needle biopsy is not only associated with complications but is costly as well. Noninvasive tests to identify acute rejection would help obviate the need for biopsies in sizable proportion of patients with allograft dysfunction.